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Zeolitic tuffs for acid mine drainage (AMD) treatment in Ecuador: breakthrough curves for Mn2+, Cd2+, Cr3+, Zn2+, and Al3+ Texte intégral
2017
Buenaño Guerra, Xavier Eduardo | Canoira López, Laureano | Martín Sánchez, Domingo Alfonso | Costafreda Mustelier, Jorge Luis
Zeolitic tuff constitutes a technical and economical feasible alternative to manage acidic waters in initial phases of generation. A study of cation exchange with two zeolitic tuffs from Ecuador and one from Cuba has been conducted using breakthrough curve methodology. Cations Mn2+, Cd2+, Cr3+,Zn2+, and Al3+ have been chosen owing to their presence in underground water in exploration activities (decline development)in Fruta del Norte (Ecuador). Zeolites characterized by X-ray diffraction and thermal stability after heating overnight as heulandites show a similar exchange behavior for the five cations studied. The clinoptilolite sample Tasajeras shows a relevant cation exchange performance expressed in the important increment of spatial time to reach the breakthrough point in comparison with heulandite samples. The maximum length of unused beds was found for Cr3+ and Zn2+ cations showing,therefore, a lower adsorption performance in relation with Mn2+ and Cd2+. A final disposal method of metal-loaded zeolites with cement is proposed. Keywords Natural zeolites . Acidic mine waters . Cation exchange capacity . Cation saturation curves . Metal-loaded zeolites . Cement pozzolanic additives
Afficher plus [+] Moins [-]Simultaneous determination of multiclass emerging contaminants in aquatic plants by ultrasound assisted matrix solid phase dispersion and GC-MS Texte intégral
2016
Aznar Roca, Ramón | Albero, Beatriz | Sánchez Brunete, Consuelo | Miguel, Esther | Martín Girela, Isabel | Tadeo, José L.
A multiresidue method was developed for the simultaneous determination of 31 emerging contaminants (pharmaceutical compounds, hormones, personal care products, biocides and flame retardants) in aquatic plants. Analytes were extracted by ultrasound assisted-matrix solid phase dispersion (UA-MSPD) and determined by gas chromatography-mass spectrometry after sylilation. The method was validated for different aquatic plants (Typha angustifolia, Arundo donax and Lemna minor) and a semiaquatic cultivated plant (Oryza sativa) with good recoveries at concentrations of 100 and 25 ng g-1 wet weight, ranging from 70 to 120 %, and low method detection limits (0.3 to 2.2 ng g-1 wet weight). A significant difference of the chromatographic response was observed for some compounds in neat solvent versus matrix extracts and therefore quantification was carried out using matrix-matched standards in order to overcome this matrix effect. Aquatic plants taken from rivers located at three Spanish regions were analyzed and the compounds detected were parabens, bisphenol A, benzophenone-3, cyfluthrin and cypermethrin. The levels found ranged from 6 to 25 ng g-1 wet weight except for cypermethrin that was detected at 235 ng g-1 wet weight in Oryza sativa samples.
Afficher plus [+] Moins [-]A comparative study between the fluxes of trace elements in bulk atmospheric deposition at industrial, urban, traffic, and rural sites Texte intégral
2015
Fernández Olmo, Ignacio | Puente García, Mariano | Irabien Gulías, Ángel | Universidad de Cantabria
The input of trace elements via atmospheric deposition towards industrial, urban, traffic, and rural areas is quite different and depends on the intensity of the anthropogenic activity. A comparative study between the element deposition fluxes in four sampling sites (industrial, urban, traffic, and rural) of the Cantabria region (northern Spain) has been performed. Sampling was carried out monthly using a bulk (funnel bottle) sampler. The trace elements, As, Cd, Cr, Cu, Mn, Mo, Ni, Pb, Ti, Zn, and V, were determined in the water soluble and insoluble fractions of bulk deposition samples. The element deposition fluxes at the rural, urban, and traffic sites followed a similar order (Zn>Mn>>Cu=Ti>Pb>V=Cr>Ni>>As=Mo>Cd). The most enriched elements were Cd, Zn, and Cu, while V, Ni, and Cr were less enriched. An extremely high deposition of Mn was found at the industrial site, leading to high enrichment factor values, resulting from the presence of a ferro-manganese/silicomanganese production plant in the vicinity of the sampling site. Important differences were found in the element solubilities in the studied sites; the element solubilities were higher at the traffic and rural sites, and lower at the urban and industrial sites. For all sites, Zn and Cd were the most soluble elements, whereas Cr and Ti were less soluble. The inter-site correlation coefficients for each element were calculated to assess the differences between the sites. The rural and traffic sites showed some similarities in the sources of trace elements; however, the sources of these elements at the industrial and rural sites were quite different. Additionally, the element fluxes measured in the insoluble fraction of the bulk atmospheric deposition exhibited a good correlation with the daily traffic volume at the traffic site. | The authors are grateful for the financial support from the CTM 2010-16068 (Spanish Ministry of Science and Innovation) and CTM 2013-43904 R (Spanish Ministry of Economy and Competitiveness) projects. The “Consejería de Medio Ambiente” from the Cantabria Government is also acknowledged for sending the report on the background levels of heavy metals and trace elements in soils in the Cantabria region. The authors are also grateful to “Ayuntamiento de Camargo” for helping us with the sampling site of Maliaño.
Afficher plus [+] Moins [-]Persistent organic pollutants in four bivalve species from Svalbard waters Texte intégral
2012
Vieweg, Ireen | Hop, Haakon | Brey, Thomas | Huber, Sandra | Ambrose, William G. | Locke, William L.
Organochlorine compounds (OC) were determined in Arctic bivalves (Mya truncata, Serripes groenlandicus, Hiatella arctica, Chlamys islandica) from Svalbard with regard to differences in geographic location, species and variations related to their size and age. Higher chlorinated polychlorinated biphenyls (PCB 101- PCB 194), chlordanes and α-hexachlorocyclohexane (α-HCH) were consistently detected in the bivalves and PCBs dominated the OC load in the organisms. OC concentrations were highest in Mya truncata and the lowest in Serripes groenlandicus. Species-specific OC levels were likely related to differences in the species' food source, as indicated by the δ13C results, rather than size and age. Higher OC concentrations were observed in bivalves from Kongsfjorden compared to the northern sampling locations Liefdefjorden and Sjuøyane. The spatial differences might be related to different water masses influencing Kongsfjorden (Atlantic) and the northern locations (Arctic), with differing phytoplankton bloom situations.
Afficher plus [+] Moins [-]Vertical Flow Constructed Wetlands fed with raw sewage: historical review and recent developments in France Texte intégral
2010
Liénard, A.
This paper relates to the 1st studies conducted in France on Vertical Flow Constructed Wetlands [VFCWs]. This process was originally designed by Käte Seidel according to her previous research done in Krefeld (Germany) the so-called Max Planck Institute Process [MPIP]. Based on measurements campaigns done successively in Saint Bohaire and Pont-Rémy, it was clearly established that the vertical flow 1st stage filters were significantly more efficient than the horizontal ones. This acknowledgement of success was positively used to design a treatment plant in Gensac la Pallue, still in operation after 23 years, with the special feature that the VFCW are fed with raw sewage. This attribute was then spread to the design of French VFCW systems. The main reasons which explain why representatives of small communities are so enthusiastic about feeding with raw sewage are presented. The state of the art of French VFCWs is detailed and scientific arguments which nowadays lead to new fields of application and a better understanding of small scale processes which occurs in these filters are also suggested.
Afficher plus [+] Moins [-]Phosphorus removal by the use of apatite in constructed wetlands: design recommendations. | Rétention du phosphore par apatite en filtres plantés de roseaux : recommandations de dimensionnement Texte intégral
2010
Molle, Pascal | Martin, S. | Esser, D. | Besnault, S. | Morlay, C | Harouiya, N.
Phosphorus (P) removal in constructed wetlands (CWs) has received particular attention during the last decades by using specific materials which promote P adsorption/precipitation phenomena. Recent studies have shown an interest in using apatite materials to promote P precipitation onto their surface. About ten years of experiments at different scales (laboratory, pilot, full scale) have passed. The process is now open in France. This paper presents the first design recommendations according to the apatite mineral quality and treatment outlet requirements. Kinetics and their evolution with the material saturation degree are presented based on the k-C* model. The process can achieve 1 mgP.l-1 for long term while using surface P removal filter area of 0.5 m².p.e.-1. With a low land footprint and high P removal efficiency, the interest of the process also result in the orthophosphates accumulation on a phosphate mineral which makes easier to reuse phosphorus from wastewater once saturated.
Afficher plus [+] Moins [-]Use of bile PAH metabolites as a biomarker of pollution in fish from the Baltic Sea Texte intégral
2006
Vuorinen, P. J. | Keinänen, M. | Vuontisjärvi, H. | Baršienė, J. | Broeg, Katja | Förlin, L. | Gercken, J. | Kopecka, J. | Köhler, Angela | Parkkonen, J. | Pempkowiak, J. | Schiedek, D.
The Elbe flood 2002-toxic effects of transported contaminants in flatfish and mussel of the Wadden Sea Texte intégral
2005
Einsporn, Sonja | Broeg, Katja | Köhler, Angela
Design criteria and performances of reed bed filters for the treatment of washing parlour effluents Texte intégral
2002
Lienard, A. | Esser, D. | Houdoy, D. | Sabalcagaray, P.
Conçus initialement pour le traitement des eaux usées domestiques, les filtres plantés de roseaux ont été adaptés pour le traitement des effluents de lavage de salles de traite pour fournir une alternative au stockage et épandage. Pour simplifier les système en vue de réduire les coûts d'investissement, plusieurs sites expérimentaux ont été construits, modifiés si nécessaire et suivis. Placé à la suite d'une fosse toutes eaux de 3 à 9 m3, la configuration la plus aboutie consiste en 2 étages des filtres plantés à flux verticaux chacun étant composé de 2 filtres alimentés en alternance chaque semaine. La surface totale active correspond à 0.25m2 par vache laitière pour les eaux blanches seules (machine à traire et tank à lait) et 0.4m2 par vache lorsque s'y ajoutent les eaux vertes de lavage des quais et murs de la salle de traite. Les filtres du 1er étage occupent 65% de la surface totale. Observées dans 3 exploitations agricoles laitières, les concentrations obtenues atteignent une fourchette de 50 à 180 mg/L en DCO, 5 à 75 mg/L en DBO5 et 10 à 60 mg/L en MES. La nitrification qui est considérée comme un bon indicateur du potentiel d'oxydo-réduction dans le réacteur n'est certes pas complète mais beaucoup plus élevée que dans le cas de filtres à sable étudiés pour le même objectif alors que plusieurs d'entre eux ont colmaté. / Initially designed for the treatment of domestic wastewater, Vertical Flow Reed Bed Filters [VFRBF] have been adapted for washing parlour effluents to study the feasibility of the treatment of such effluents instead of their storage and land spreading. It was necessary to adapt the design of VFRBF to minimise the investment costs. Several experimental sites have been built, monitored and progressively adapted. Following a septic tank of 3 to 9 m3, the best design was considered to be: 2 stages of VFRBF in series each composed of 2 filters which are alternately fed on a weekly rhythm. The total active area is approximately equivalent to 0.25 m2 per milking cow for the washing effluent of the milking machine and milk-storage tank and 0.4 m2 per milking cow when the washing effluents from the floor and walls of the milking parlour are added to the previous ones. The 1st stage filters takes up 65 % of the total area. Based on a survey done in 3 farms, the concentrations achieved a range of 50 to 180 mgL-1 in COD, 5 to 75 mgL-1 in BOD5, 10 to 60 mgL-1 in SS. The nitrification, which can be considered as a good indicator of the redox potential within the filter media, was not complete but much more effective than in sand filters studied for the same purpose but some of them have clogged.
Afficher plus [+] Moins [-]Phosphorus sorption in subsurface constructed wetlands: investigations focused on calcareous materials and their chemical reactions Texte intégral
2002
Molle, Pascal | Lienard, A. | Grasmick, A. | Iwema, A.
Phosphorus removal from wastewater has been of growing interest for some decades to avoid eutrophication in surface water. In subsurface constructed wetlands precipitation and adsorption are the main mechanisms responsible of P uptake. The use of calcareous media is attractive because of p-ca interactions. Two media (calcite and recycled crushed concrete (rcc)) were examined in batch and continuous systems. They show attractive sorption capacities using batch experiments, however experiments carried out in open reactors pointed out some limitation in retention capacities and effluent quality. rcc was sensitive to a strong dissolution leading to a quick phosphorus precipitation but induced high conductivity and ph values in the treated water. Calcite efficiency depended on the material dissolution rate, directly linked to the carbonate equilibrium of the solution. Microscopic observations of the calcite surface show crystal making of phosphorus precipitate. Crystal growth seems to be the main P uptake once materials surfaces are covered. No experimental condition allows to reach an effluent concentration below 2 mgp.l-1.
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